This investigation into significant maternal factors related to pregnancy outcome at high "risk" for congenital heart disease uses data from records of of longitudinal epidemiologic NINCDS Collaborative Perinatal Project. Observations on some 50,000 pregnancy records provide case and control data for analysis of selected maternal variables suggesting significant risk for cardiovascular anomalies. From over 500 suspect cardiacs specific diagnoses were available for some 460 cases. These include cardiac conditions as part of known syndromes. Analysis separates the various anomalies in order to clarify possible etiologies but also considers the group as a whole in the presentation of significance of the problem to society and to providers of care for handicapped children.